I had that view of converts before, that they were amazing and bright haing converted, and more genuine than Muslims. But when you see the religion for what it is, converts, particularly former atheists, become the most baffling creatures. They embody all the faults of believers (servility, reductionism, etc ) but in much more acute form. On top of that, they have to adopt all the backward cultural traits. So I came to the conclusion that all converts were looking for a club and new set of friends, or had grown up around Muslims and wanted to join their ranks.
Converts from other religions, however, are a fairly reasonable and easy to understand phenomenon.
The truth is that no one knows how many people convert each year or how many people leave each year and what gender or race they are. Plenty of people convert, live, and leave as solitary Muslims on the fringe of a community. But based on what I've seen over the years of my adulthood, I think the reason female converts who leave seem more obvious is because it often coincides with the end of a marriage. Not that women are leaving just because they get divorced, but rather, the divorce is the result of the apostasy. Also, again in my experience, you see women waiting until their kids are grown and then 'suddenly' they get a divorce and leave Islam. Of course, they were just waiting until they could be assured that there wouldn't be a 'Not Without my Daughter' situation.
You see an Asian really into it, and it's 'Oh right, yeah,' but if you see a convert who's really into it, it's 'Oh, they converted and now they're more Muslim than the Muslims'. The converts who don't get into the religion too much, and there are a lot of them, are much less visible, on the other hand, because they do blend into the regular society. Also, I have to point out that there is a lot more pressure placed on converts by the Muslim community to be super-religious, whereas an Arab or Asian brother can go off and sell liquor in his store and have a girlfriend and nobody bats an eye. Because of the natural lack of knowledge, it's probably natural then for a convert to be 'super Islamic' at least for a while. I knew plenty of converts who started out 'super Muslim' and gradually became more relaxed or liberal the way lots of Arab, Turkish, and Asian people were as they learned more or practised more of the religion
However, to be honest, I think that a lot of people who convert to Islam do have emotional and mental issues. Not all, but a fair amount. Is that a cause? I have definitely seen a lot of people who converted to Islam with mental illnesses, and I think they desired the comfort of a highly structured life where decisions are made for you - how to dress, how to eat, and so on.